src/sys/vm/vm_object.c, branch release/2.2.8

Small change in DDB function code to deal with new definition of TAILQ_PREV.

1998-05-06T19:16:42Z

1. Fix the vm_page_zero_count accounting. This should improve the

1997-03-25T04:54:38Z

performance of the pre-zero loop. 2. Fix madvise. It had a myriad of bugs, including the potential for system crashes. 3. Improve vm_map handling. This is a result of work done by both (Alan Cox) and me. Earlier versions of the map handling code was very unintelligent about map coalescing. 4. Support a working and closer to POSIX mlock. 5. A couple of performance enhancements that came along for the ride, including changing certain bitfields to flags in vm_map. 6. Bring procfs up to date with respect to the changes. This code has been carefully extracted from -current. Reviewed by: David Greenman

Reviewed by:

1996-09-28T03:33:40Z

Submitted by: Obtained from:

Attached vm ddb commands `show map', `show vmochk', `show object',

1996-09-14T11:54:59Z

`show vmopag', `show page' and `show pageq'. Moved all vm ddb stuff to the ends of the vm source files. Changed printf() to db_printf(), `indent' to db_indent, and iprintf() to db_iprintf() in ddb commands. Moved db_indent and db_iprintf() from vm to ddb. vm_page.c: Don't use __pure. Staticized. db_output.c: Reduced page width from 80 to 79 to inhibit double spacing for long lines (there are still some problems if words are printed across column 79).

Addition of page coloring support. Various levels of coloring are afforded.

1996-09-08T20:44:49Z

The default level works with minimal overhead, but one can also enable full, efficient use of a 512K cache. (Parameters can be generated to support arbitrary cache sizes also.)

Even though this looks like it, this is not a complex code change.

1996-08-21T21:56:23Z

The interface into the "VMIO" system has changed to be more consistant and robust. Essentially, it is now no longer necessary to call vn_open to get merged VM/Buffer cache operation, and exceptional conditions such as merged operation of VBLK devices is simpler and more correct. This code corrects a potentially large set of problems including the problems with ktrace output and loaded systems, file create/deletes, etc. Most of the changes to NFS are cosmetic and name changes, eliminating a layer of subroutine calls. The direct calls to vput/vrele have been re-instituted for better cross platform compatibility. Reviewed by: davidg

Backed out the recent changes/enhancements to the VM code. The

1996-07-30T03:08:57Z

problem with the 'shell scripts' was found, but there was a 'strange' problem found with a 486 laptop that we could not find. This commit backs the code back to 25-jul, and will be re-entered after the snapshot in smaller (more easily tested) chunks.

This commit is meant to solve a couple of VM system problems or

1996-07-27T03:24:10Z

performance issues. 1) The pmap module has had too many inlines, and so the object file is simply bigger than it needs to be. Some common code is also merged into subroutines. 2) Removal of some *evil* PHYS_TO_VM_PAGE macro calls. Unfortunately, a few have needed to be added also. The removal caused the need for more vm_page_lookups. I added lookup hints to minimize the need for the page table lookup operations. 3) Removal of some bogus performance improvements, that mostly made the code more complex (tracking individual page table page updates unnecessarily). Those improvements actually hurt 386 processors perf (not that people who worry about perf use 386 processors anymore :-)). 4) Changed pv queue manipulations/structures to be TAILQ's. 5) The pv queue code has had some performance problems since day one. Some significant scalability issues are resolved by threading the pv entries from the pmap AND the physical address instead of just the physical address. This makes certain pmap operations run much faster. This does not affect most micro-benchmarks, but should help loaded system performance *significantly*. DG helped and came up with most of the solution for this one. 6) Most if not all pmap bit operations follow the pattern: pmap_test_bit(); pmap_clear_bit(); That made for twice the necessary pv list traversal. The pmap interface now supports only pmap_tc_bit type operations: pmap_[test/clear]_modified, pmap_[test/clear]_referenced. Additionally, the modified routine now takes a vm_page_t arg instead of a phys address. This eliminates a PHYS_TO_VM_PAGE operation. 7) Several rewrites of routines that contain redundant code to use common routines, so that there is a greater likelihood of keeping the cache footprint smaller.

Various bugfixes/cleanups from me and others:

1996-06-16T20:37:31Z

1) Remove potential race conditions on waking up in vm_page_free_wakeup by making sure that it is at splvm(). 2) Fix another bug in vm_map_simplify_entry. 3) Be more complete about converting from default to swap pager when an object grows to be large enough that there can be a problem with data structure allocation under low memory conditions. 4) Make some madvise code more efficient. 5) Added some comments.

This commit is dual-purpose, to fix more of the pageout daemon

1996-05-31T00:38:04Z

queue corruption problems, and to apply Gary Palmer's code cleanups. David Greenman helped with these problems also. There is still a hang problem using X in small memory machines.